PriorityQueue extends AbstractQueue and implements the Queue interface. It creates a queue that is prioritized based on the queue’s comparator. PriorityQueue is a generic class that has this declaration:
class PriorityQueue<E>
Here, E specifies the type of objects stored in the queue. PriorityQueues are dynamic, growing as necessary.
PriorityQueue defines the six constructors shown here:
PriorityQueue( )
PriorityQueue(int capacity)
PriorityQueue(int capacity, Comparator<? super E> comp)
PriorityQueue(Collection<? extends E> c)
PriorityQueue(PriorityQueue<? extends E> c)
PriorityQueue(SortedSet<? extends E> c)
The first constructor builds an empty queue. Its starting capacity is 11. The second constructor builds a queue that has the specified initial capacity. The third constructor builds a queue with the specified capacity and comparator. The last three constructors create queues that are initialized with the elements of the collection passed in c. In all cases, the capacity grows automatically as elements are added